In the previous chapter, we had a look at the variable; now we have just looked at how to correlate them. Assigning values and being able to perform some math or logic operations on them gives us more flexibility, since we do not just collect something, but transform it into something different and new. We also learned that exit codes can sometimes be pitfalls, trapping us with red herrings, and this tells us something important: never take anything as a given, always double-check what you are writing in your code, and always try to catch all the possible outcomes and exceptions. It seems like something obvious, but being such common sense, we tend to overlook this simple but effective code style advice.
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